In recent years, for example, liquid crystal display devices are used widely for liquid crystal TVs, monitors, mobile telephones, etc. as flat panel displays having features such as thinness and light weight, compared with conventional Braun tubes. In such a liquid crystal display device, it is known that an active matrix substrate, which is provided with a plurality of data wiring lines (source wiring lines) and a plurality of scanning wiring lines (gate wiring lines) arranged in a matrix, and pixels arranged in a matrix, each having a switching element such as a thin film transistor (TFT) disposed in the vicinity of the intersection of the data wiring line and the scanning wiring line and a pixel electrode connected to the switching element, is used for a liquid crystal panel as a display panel.
Further, in such an active matrix substrate, in order to enhance the display quality in the liquid crystal display device, there is a demand that a sufficient auxiliary capacity be added to the pixel electrodes and the opening ratio of the pixels be increased.
Further, in the conventional active matrix substrate, for example, as described in the following Patent document 1, it is proposed that first and second transparent conductive patterns be provided so as to sandwich a gate insulating film, and an auxiliary capacity be generated between the first and second transparent conductive patterns. Further, in the conventional active matrix substrate, an auxiliary capacity line (auxiliary capacity wiring line) is connected to the second transparent electrode pattern, and an end of the first transparent electrode pattern is directly laminated on a source electrode of the thin film transistor without providing a contact hole. Further, in the conventional active matrix substrate, a contact hole for bringing the pixel electrode and the first transparent electrode pattern into conduction is provided at a portion where the second transparent electrode pattern and the auxiliary capacity line overlap each other, and an island-shaped pattern including a semiconductor layer is provided on the gate insulating film. Then, the conventional active matrix substrate enables a sufficient auxiliary capacity to be ensured and the opening ratio of the pixels to be increased.